The present invention relates to an ink for electronic component used in various electronic appliances such as laminate ceramic capacitor, LC filter, and complex high frequency component, a manufacturing method of electronic component by using this ink for electronic component, and an ink jet device.
In a laminate ceramic electronic component which is a conventional example of electronic component, an electrode ink is printed and formed in a specified pattern as an internal electrode on. a ceramic green sheet composed of ceramic powder, polyvinyl butyral resin, and a slight portion of plasticizer, and a specified number of sheets are laminated, cut, and baked, and an external electrode is formed. As such electrode ink, various types have been proposed for screen printing, including, for example, an ink for internal electrode of laminate ceramic capacitor for screen ink prepared by kneading nickel metal powder by three rolls as disclosed in Japanese Laid-open Patent No. 5-205970, and an electrode ink for screen ink using ceramic powder coated with palladium proposed in Japanese Laid-open Patent No. 5-275263.
Further in Japanese Laid-open Patent No. 5-55075, a conductor paste containing nickel oxide is proposed for screen printing technology. In Japanese Laid-open Patent No. 5-90069, it is proposed to add rosin to a conductive paste for screen. Also in Japanese Laid-open Patent No. 5-226179, it is proposed to add scaly powder to a conductor paste for screen. In Japanese Laid-open Patent No. 5-242724, similarly, a conductive paste for screen by adding organic phosphoric acid is proposed. In Japanese Laid-open Patent No. 5-275263, coating zirconia powder with nickel or other base metal, a conductive paste for screen printing is proposed. In Japanese Laid-open Patent No. 5-299288, using polyether urethane resin, a manufacturing method of laminate ceramic capacitor for screen printing of internal electrode is proposed.
In the manufacturing method of laminate ceramic electronic component such as laminate ceramic capacitor, the internal electrode has been printed and formed by screen printing, but in order to lower the cost and enhance the performance, a gravure printing process is proposed in Japanese Patent Publication No. 5-25381 or Japanese Patent Publication No. 8-8200. In U.S. Pat. No. 5,101,319, a calender processing of electrode by gravure printing for laminate ceramic capacitor is proposed.
In the conventional electrode inks (whether for screen printing or for gravure, etc.), since an organic solvent is used as the main solvent, when printed on a ceramic green sheet, the ceramic green sheet may be swollen or dissolved again by the organic solvent contained in the electrode ink. Accordingly, as far as the thickness of the ceramic green sheet is 20 xcexcm or more, it rarely causes shorting, but when the thickness of the ceramic green sheet is less than 15 xcexcm, the shorting probability is very high.
To solve this problem, hitherto, a manufacturing method of ceramic electronic component by direct gravure printing on the green sheet has been proposed, for example, as disclosed in Japanese Patent Publication No. 8-8200. In this case, however, the shorting probability is high when the ceramic green sheet is thin, and accordingly Japanese Patent Publication No. 5-25381 proposes a method of transferring a gravure printed pattern on the ceramic green sheet because the ceramic green sheet may be swollen or damaged when the electrode is directly printed on the ceramic green sheet. Thus, regardless of the printing method, in the conventional electrode ink, the ceramic green sheet was damaged, and the shorting problem was caused in thin ceramic green sheets of 15 xcexcm or less.
In the conventional ink jet device, it was designed to print by filling an ink cartridge of a commercial ink jet printer with an ink. When printed by this ink jet device, the ink often precipitated or gathered near the ink jet nozzle for injecting the ink, causing the problem of ink clogging.
The invention is to solve the problems of the prior arts, and it is hence an object thereof to present an ink for electronic component capable of preventing re-dissolving of ceramic green sheet and baking, a manufacturing method of electronic component by using this ink for electronic component, and an ink jet device.
To achieve the object, the invention comprises water or organic solvent, and one of metal powder, ceramic powder, magnetic powder, glass powder, or resistor powder with particle size of 0.001 xcexcm or more to 10 xcexcAm or less, dispersed in this water or organic solvent, by 1 wt. % or more to 80 wt. % or less, at viscosity of 2 poise or less.
Or it comprises water or organic solvent, and a resin dispersed in this water or organic solvent, by 1 wt. % or more to 80 wt. % or less, at viscosity of 2 poise or less.
The method comprises the steps of repeating a plurality of times of a process of forming a specified ink pattern on a ceramic green sheet by an ink jet method by using an ink prepared by dispersing metal powder with particle size of 0.001 xcexcm or more to 10 xcexcm or less, in at least water or organic solvent, by 1 wt. % or more to 80 wt. % or less, at viscosity of 2 poise or less, laminating a plurality of the ceramic green sheets forming this ink pattern to form a raw laminated body of ceramic, cutting to specified shape and baking, and forming an external electrode.
Or the method comprises the steps of repeating a plurality of times of a process of forming a specified first ink pattern on a ceramic green sheet by an ink jet method by using a first ink prepared by dispersing metal powder with particle size of 0.001 xcexcm or more to 10 xcexcm or less, in at least water or organic solvent, by 1 wt. % or more to 80 wt. % or less, at viscosity of 2 poise or less, and forming a specified second ink pattern by an ink jet method by using a second ink prepared by dispersing ceramic powder with particle size of 0.001 xcexcm or more to 10 xcexcm or less, in at least water or organic solvent, by 1 wt. % or more to 80 wt. % or less, at viscosity of 2 poise or less, laminating a plurality of the ceramic green sheets forming these ink patterns to form a raw laminated body of ceramic, cutting to specified shape and baking, and forming an external electrode.
Further, the method comprises the steps of repeating a plurality of times of a process of forming a specified ink pattern on a ceramic green sheet by a gravure printing method by using an ink prepared by dispersing metal powder with particle size of 0.001 xcexcm or more to 10 xcexcm or less, in at least water or organic solvent, by 1 wt. % or more to 80 wt. % or less, at viscosity of 2 poise or less, laminating a plurality of the ceramic green sheets forming this ink pattern to form a raw laminated body of ceramic, cutting to specified shape and baking, and forming an external electrode.
Or the method comprises the steps of repeating a plurality of times of a process of forming a specified first ink pattern on a ceramic green sheet by an ink jet method by using a first ink prepared by dispersing metal powder with particle size of 0.001 xcexcm or more to 10 xcexcm or less, in at least water or organic solvent, by 1 wt. % or more to 80 wt. % or less, at viscosity of 2 poise or less, forming a specified second ink pattern by an ink jet method by using a second ink prepared by dispersing ceramic powder with particle size of 0.001 xcexcm or more to 10 xcexcm or less, in at least water or organic solvent, by 1 wt. % or more to 80 wt. % or less, at viscosity of 2 poise or less on the upper surface of the ceramic green sheet so as to cover this first ink pattern, and forming a ceramic layer integrated with the ceramic green sheet, laminating a desired plurality of the ceramic green sheets having the ceramic layer to form a raw laminated body of ceramic, cutting to specified shape and baking, and forming an external electrode.
Also, the method comprises the steps of forming a pair of upper electrode layers on a confronting upper side of a substrate by an ink jet method, forming a resistance layer so as to straddle over the upper electrode layers by an ink jet method by using an ink prepared by dispersing resistance powder with particle size of 0.001 xcexcm or more to 10 xcexcm or less, in at least water or organic solvent, by 1 wt. % or more to 80 wt. % or less, at viscosity of 2 poise or less, and forming a glass projective layer at least to cover this resistance layer by an ink jet method by using an ink prepared by dispersing glass powder with particle size of 0.001 xcexcm or more to 10 xcexcm or less, in at least water or organic solvent, by 1 wt. % or more to 80 wt. % or less, at viscosity of 2 poise or less.
Also, the method comprises the steps of forming a pair of upper electrode layers on a confronting upper side of a substrate by an ink jet method, forming a resistance layer so as to straddle over the upper electrode layers by an ink jet method by using an ink prepared by dispersing resistance powder with particle size of 0.001 xcexcm or more to 10 xcexcm or less, in at least water or organic solvent, by 1 wt. % or more to 80 wt. % or less, at viscosity of 2 poise or less, and forming a glass projective layer at least to cover this resistance layer by an ink jet method by using an ink prepared by dispersing a resin, in at least water or organic solvent, by 1 wt. % or more to 80 wt. % or less, at viscosity of 2 poise or less.
Also, the method comprises the steps of injecting a magnetic ink prepared by dispersing magnetic powder with particle size of 0.001 xcexcm or more to 10 xcexcm or less, in at least water or organic solvent, by 1 wt. % or more to 80 wt. % or less, at viscosity of 2 poise or less, and an electrode ink alternately in a specified pattern by an ink jet method, forming a block body of a three-dimensional structure having the electrode ink printed inside in a coil form so as to cover the electrode ink with the magnetic ink, and cutting this block body into a specified form and baking.
Also, the method comprises the steps of forming a ceramic green sheet having an electrode pattern by repeating a plurality of times of a process of injecting an electrode ink by an ink jet method from the upper surface of a ceramic green sheet having a base film with a penetrating via hole and forming an electrode pattern on the upper surface of this ceramic green sheet and in the via hole, and a process of filling at least the via hole with the electrode pattern and peeling off the base film, laminating a desired number of the ceramic green sheets having the electrode pattern so as to connect between the upper and lower electrode patterns electrically to form a raw laminated body of ceramic, cutting into a specified shape and baking, and forming an external electrode.
The invention also presents an apparatus comprising an ink tank filled with an ink, a first tube for sucking the ink in this ink tank through a suction mechanism, an ink injection unit connected to this first tube for injecting a required amount of the ink, and a second tube connected to this ink injection unit for circulating the ink not injected from the ink injection unit into the ink tank.
Also, the apparatus comprises a dispersing machine filled with an ink, a first tube for sucking the ink in this dispersing machine through. a suction mechanism, an ink injection unit connected to this first tube for injecting a required amount of the ink, and a second tube connected to this ink injection unit for circulating the ink not injected from the ink injection unit into the dispersing machine.